In a pointer from this blog post on Adam Trachtenberg's site today, there's a story of some struggles that Tim Bray has been having when it comes to online calenders and coordinating with those in his life.
Here’s the problem: Dr. Wood and I both have complicated jobs plus we have a family, so just like everyone else in the world, keeping in sync is a problem. Herewith a painful half-finished story of trying to solve it with technology. The conclusion is painfully obvious: whoever first provides a family-scheduling tool that non-geeks can use and Just Works with the tools most people run their calendars on is going to make a lot of money and do Humanity a major service.